کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6455220 | 1419161 | 2017 | 7 صفحه PDF | دانلود رایگان |
- The anion effect of 4 electrolytes for CO2RR on Au catalyst are investigated.
- The specific adsorption of anions could contribute to suppressing HER.
- Chloride anion plays a notable role as increasing CO/H2 production ratio.
- Phosphate anion contributes to decrease CO/H2 production ratio.
In this study, we first demonstrate that CO production selectivity from CO2 on Au electro-catalyst depends on the type of electrolyte anion. Comparing the faradaic efficiencies of H2, HCOOâ and CO in the presence of different anions such as Clâ, HPO42â, SO42â and HCO3â at constant potential of â0.7Â V (vs. RHE), we observe that the CO/H2 ratio could be enhanced due to strongly adsorbed anion such as Clâ. Although HPO42â is more strongly adsorbed than SO42â and HCO3â on the surface of electrode, CO2 reduction in HPO42â containing solution exhibited a minimum faradaic efficiency of CO (11%) but a maximum faradaic efficiency of H2 (70%). Based on physicochemical analytical tools (LSV, EIS, SEM, XPS and XRD) and according to previous studies, we conclude that the product distribution is associated with distinct properties caused by characteristic of each anion when adsorbed on the electrode surface such as specific adsorption strength and intrinsic characteristic of anions.
Depending on electrolytes containing different anions, CO/H2 production ratio of CO2 electroreduction on Au catalyst was differently observed. Usually, a specific adsorption strength of anions played a key role in determination of CO/H2 ratio by a suppressing hydrogen evolution reaction. However, unlike that, certain anions such as chloride and phosphate differently contribute to increase CO/H2 ratio due to their intrinsic characteristics.97
Journal: Catalysis Today - Volume 295, 15 October 2017, Pages 82-88